WO2002055631A1 - Plastic liquefying device - Google Patents

Abstract

A plastic liquefying device, comprising a gasifying furnace (19) for generating pyrolytic gas by heating and melting plastic waste and a liquefying tank (2) for liquefying and separating the pyrolytic gas generated in the gasifying furnace (19), the gasifying furnace (19) further comprising a heating means (22) for heating the inside of an oven-shaped furnace body (20) provided at the bottom of the furnace body (20) having a plastic waste inlet (H) provided at the top thereof and an opening and closing mechanism (21) for opening and closing the inlet (H) installed at the inlet (H), the opening and closing mechanism (21) further comprising a platy shutter (24) larger than at least the opening area of the inlet (H) and a fixing means (25) for pressingly fixing the shutter (24) to the seal surface (S) around the peripheral edge part of the inlet (H), whereby, since the inside of the furnace body (20) can be sealed by closely fitting the shutter (24) to the seal surface (S), the lowering of a pressure inside the furnace due to gas leakage and the deterioration of an ambient environment can be prevented beforehand.

Description

 Specification

 Plastic oil processing technology

 TECHNICAL FIELD The present invention relates to an apparatus for converting plastic waste into a plastic oil for effectively utilizing it as a recycled oil by subjecting it to thermal decomposition.

Background technology

 In recent years, one of the most important issues in the increasing number of garbage disposal measures is the plastic parts and plastics used in most industrial products such as electrical products, household goods, automobiles, PET bottles, etc. There is disposal of container.

 That is, such waste plastic is difficult to biodegrade by microorganisms such as garbage and wood trash, so most of it is currently incinerated, but as is well known, plastic is There are problems such as generating a large amount of soot and harmful gas during incineration and adversely affecting the incinerator due to the high combustion temperature. Therefore, in recent years, attempts have been made to collect this waste plastic and reuse it as one of valuable recycled resources. However, in the case of recycling, if it is not collected and sorted out, for example, for each component, color, etc. Because of the cumbersome tasks such as not working, there is a problem that it requires a great deal of cost and labor, and is not economically viable.

 Accordingly, the present inventor has developed a new waste plastic oil conversion system that can effectively dispose of such waste plastics that have been difficult to dispose and recycle, and can effectively utilize the waste plastics as recycled oil. (Japanese Patent Application No. 2000-0-633335).

As shown in Fig. 12, this waste plastic oiler has a gasifier 1 that heats and melts waste plastic by the heat of a gas burner 4 and the like, and pyrolyzes and gasifies it. It consists mainly of an liquefaction treatment tank 2 that cools and condenses the pyrolysis gas obtained in step 1 to make it oily, and mainly melts thermoplastic waste plastic in this waste plastic pyrolysis furnace 1. Into a styrene monomer or low molecular weight polyethylene. After disassembly, the pyrolysis gas is brought into gas-liquid contact with the cooling water in the liquefaction tank 2 to be cooled and condensed to be re-liquefied. And as a raw material for new plastic products.

 In other words, as shown in the figure, the inlet of gasifier 1 is opened, waste plastic is injected into it, and shirt 1-3 is closed.The waste plastic injected by the heat of burner 4 melts and liquefies. For the first time, a molten liquid is formed, and a part of it is sequentially pyrolyzed and gasified, and the pyrolyzed gas flows out of the gas outlet 5 into the gas line G, and then reaches the oil treatment tank 2. This oil treatment tank 2 has a water tank 6 for storing liquid, a jet scrubber 7 serving as a cooler, and a neutralization tower 8 integrated with each other.The pyrolysis gas reaching the oil treatment tank 2 is First, in the gas scrubber 17, the cooling water discharged from the cooling water circulation line L 2 comes into gas-liquid contact and is rapidly cooled and condensed and liquefied.Then, it becomes a decomposition liquid and is temporarily stored in the water tank 6 together with the cooling water. Can be stored.

 Next, the mixed solution of the decomposed liquid and the cooling water obtained in this way is separated into a decomposed liquid and water in a specific gravity up and down over a predetermined time, and then the decomposed liquid collected on the liquid surface side is separated. After overflowing the overflow weir 9 provided at the end of the water tank 6, it flows to the oil drain line L1 side, is filtered by the filter 10 to separate solids, and is used as regenerated oil, etc. The water collected in the recovery tank 12 and collected at the bottom is drawn out of the water tank 6 by the pump 11, sent to the jet scrubber 17 again through the cooling water circulation line L 2, and then discharged into the hot water scrubber 17. Reused as cooling water for pyrolysis gas.

On the other hand, the pyrolysis gas that could not be liquefied by the jet scrubber 7 and the harmful components such as chlorine and bromine that are not liquefied by cooling reach the neutralization tower 8 in a gaseous state, where the cooling water line: Gas recovery line after being cooled and condensed again by the cooling water newly supplied from L4 and at the same time being neutralized by neutralizing solution supplied from the neutralizing agent tank 13 and then detoxified The gas is returned to the gasifier 1 via G2, and is effectively used as fuel gas or combustion air for the gas burner 4. The flue gas generated by the gas burner 4 passes through a jacket 16 that covers the gasifier 1, flows into the flue gas line G1, is filtered and purified by a filter 14, and then released into the atmosphere. The surplus cooling water discharged and accumulated in the water tank 6 of the oil treatment tank 2 is sequentially discharged to the outside from the drain line L3.

 Therefore, according to such a waste plastic oiling apparatus, waste plastics, which had been difficult to treat in the past, can be effectively treated, and the waste plastics can be effectively used as flammable regenerated oil. Waste plastic can be recycled efficiently. In addition, since no harmful gas leaks out in principle during this treatment, it is possible to achieve excellent effects such as no risk of polluting the local environment. Reference numeral 15 in the figure is a hopper for facilitating the introduction of waste plastic.

 However, such a waste plastic oil liquefaction system still has some problems as described below.

 ①First of all, in this gasification furnace 1, after the waste plastic is put into the furnace, the inlet is closed with a plate-shaped shroud 3 to seal the inside of the furnace. As shown in FIGS. 13 (A) and 13 (B), the rails 17 and 17 formed on both sides thereof are engaged with each other, and the rails are driven by a motor and a rack and pinion system. It is designed to open and close in the horizontal direction along 17 and 17. As a result, when the chamber 3 closes the inlet, it is simply put on the sealing surface S of the inlet by its own weight, and the furnace pressure increases and a part of the pyrolysis gas is removed. There is a risk of leakage from the gap, contaminating the surrounding environment, and a decrease in the internal pressure, resulting in a decrease in the amount of pyrolysis gas supplied to the oiling section. In addition, when waste plastic is loaded, if waste plastic or dust adheres to the sealing surface S of the loading port, the shutter 3 will not be completely closed and a gap will be created between them, causing a similar problem. Can be considered.

② If solid matter (insoluble material) such as earth and sand, metal, or wood adheres to the waste plastic treated in the gasification furnace 1, the solid matter is left as a residue on the bottom of the gasification furnace 1. It is possible that not only do they accumulate or adhere, which not only reduces the furnace volume gradually, but also that the solids themselves act as heat insulators at the bottom of the furnace, significantly reducing the thermal conductivity. For this reason, it is necessary to periodically remove this residue from the furnace bottom, but since this work is performed manually, the entire system is temporarily stopped and left for a while until the gasification furnace 1 is completely cooled. After that, the worker removes the input port using a tool such as a scraper or a suction machine, so that the operation efficiency is greatly reduced and the work is troublesome.

 (3) Next, in the oil treatment tank 2, water and oil are separated by specific gravity and separated by an overflow method. For example, substances that directly solidify without passing through liquids such as terephthalic acid, which is a raw material for pet bottles, are used. In this case, this remains as it is at the bottom of the water tank 6, making it difficult to separate and collect. As a result, the types of plastics that can be treated are limited, and waste plastics mixed with various types of plastics need to be separated before treatment.

 所 定 Also, when processing infectious waste plastic such as syringes and catheters generated from medical institutions such as hospitals and clinics, which are likely to have After a certain period of sterilization under high pressure, it is necessary to dispose of the waste.However, if this is treated in the same way as ordinary waste plastic using the above-mentioned oiling equipment, the waste will be treated at the initial stage of treatment. The infectious pathogens adhering to the surface may flow out to the side of the liquefaction treatment tank 2 together with the steam without being sufficiently killed, and may contaminate the inside of the equipment or may be mixed into the regenerated oil alive. There is.

Disclosure of the invention.

The present invention relates to a plasticizer comprising a gasifier for heating and melting waste plastic to generate a pyrolysis gas, and an oil treatment tank for liquefying and separating the pyrolysis gas generated in the gasifier. In the apparatus, the gasification furnace has a heating means for heating the inside of the furnace main body at the bottom of a kiln-shaped furnace main body having a waste plastic input port at an upper portion, and an opening / closing mechanism for opening and closing the furnace at the input port. The opening / closing mechanism includes a plate-shaped shirt at least larger than the opening area of the inlet, and fixing means for pressing and fixing the shirt against the sealing surface of the inlet peripheral edge. It has the following. As a result, the inlet of the waste plastic can be reliably sealed, so that the pressure drop in the furnace body due to gas leakage and the deterioration of the surrounding environment due to gas leakage of pyrolysis gas can be reliably prevented.

 Further, a sliding means for sliding the shutter horizontally in the horizontal direction to open and close the charging port, for example, one end is connected to the shirt evening side and the other end is swingable to the furnace body side. If a connected hydraulic cylinder is used, its inlet can be quickly opened and closed.

 Also, if a hydraulic cylinder is used as the fixing means, which presses the shirt shirt against the sealing surface from above to fix it, the shirt shirt can be closed securely. In addition, if a purge gas header that blows a purge gas onto the sealing surface is provided at the periphery of the charging port, it is possible to reliably prevent dust or the like from being inserted into the sealing surface and impairing the sealing performance.

 In addition, if the bottom of the furnace body is formed in a concavo-convex shape in which a plurality of gutter members are arranged in parallel, the surface area is increased, and the heat transfer characteristics from the heating means to the furnace body are improved and the efficiency is improved. Heat melting treatment can be performed.

 Also, if a gutter-shaped discharge path is provided at the end of each of the gutter-shaped members, and a screw conveyor is provided in each of the gutter-shaped members and the discharge path, the gutter-shaped member is collected at the bottom of the furnace body. Solid matter that is not melted can be easily discharged, thereby preventing a decrease in the volume in the furnace body and a decrease in heat transfer characteristics.

 Further, if the heating means comprises a gas burner, and a jacket for flowing the combustion exhaust gas from the gas burner is provided around the furnace body, and a spiral partition plate is provided in the jacket, the heat from the heating means is provided. Is efficiently transmitted to the furnace body, and the heating and melting efficiency is further improved.

Next, another invention is provided with a gasifier for heating and melting waste plastic to generate a pyrolysis gas, and an oil treatment tank for liquefying and separating the pyrolysis gas generated in the gasifier. In the plastic oil converter, the gasification furnace is a vertical tubular furnace body into which infectious waste plastic is charged, and the furnace body is heated from the surroundings to thermally decompose infectious waste plastic to pyrolysis. Heating means for generating gas; A stirrer for stirring, and an inlet for charging the infectious waste plastic, an opening / closing lid for opening and closing the same, and a gas outlet for discharging the pyrolysis gas at the top of the furnace body, and An automatic on-off valve is provided at the gas outlet.

 As a result, the inside of the furnace body can be sealed and the inside can be filled with high-pressure steam, so that sterilization and disinfection of infectious pathogens attached to waste plastic can be reliably performed.

 In addition, if the furnace main body is formed of a pressure vessel having a hemispherical metal end plate above and below a vertical cylindrical metal body, and provided with the opening / closing lid and a gas outlet at the top thereof, However, the pressure inside the furnace body can be safely increased.

 Further, the stirrer comprises a drive shaft located at the axis of the furnace body, a drive motor for rotating the drive shaft, and a plurality of stirring blades extending radially from the drive shaft, and If the rotating blades are configured to rotate while contacting the bottom surface of the furnace body, it is possible to stir the inside during heating and melting to carry out efficient pyrolysis treatment, and to collect solid matter accumulated in the furnace bottom. It is possible to prevent the heat transfer characteristics from deteriorating due to the adhesion of the like.

 Further, if a discharge port for discharging insoluble matter is provided at the bottom of the furnace body, solids and the like accumulated at the furnace bottom can be easily taken out by driving the stirrer. Time-consuming cleaning work in the furnace body can be omitted. Still another object of the present invention is to provide a gasification furnace for generating pyrolysis gas by simultaneously heating and melting various kinds of waste plastics, and an oily treatment for condensing and separating the pyrolysis gas generated in the gasification furnace. In a plastic oiling apparatus provided with a paddle, the gasification furnace has a bottom surface constricted in a valley shape and a bottom portion provided with a screw conveyor and a hole for discharging solids.

 Even with this, the unmelted solids accumulated at the bottom of the furnace main body can be easily discharged simply by driving the screw conveyor, thereby avoiding a decrease in the volume inside the furnace main body and a decrease in heat transfer characteristics. be able to.

In addition, the oil treatment tank is provided with a jet scrubber for spraying cooling water to the introduced pyrolysis gas and condensing it in a horizontally long water tank, and a washing tower for washing exhaust gas. The bottom of the tank is funnel-shaped and a drain line is connected to the bottom and an oil recovery line is connected to the middle part of the tank, so that oil and water can be separated, of course. Even a substance having a specific gravity higher than that of water can be reliably separated.

 Also, if a neutralizer tank for injecting a neutralizer into the drain line is provided, the separated water can be effectively neutralized.For example, if the water becomes acidic, the piping system will be oxidized. Problems such as corrosion can be avoided beforehand.

BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a longitudinal sectional view showing one embodiment of a gasification furnace of the apparatus of the present invention.

 FIG. 2 is a sectional view taken along line AA in FIG.

 FIG. 3 is a sectional view taken along the line Y--Y in FIG.

 FIG. 4 is a sectional view taken along line Y--Y in FIG.

 FIG. 5 is a partially enlarged view showing a portion A in FIG.

 FIG. 6 is a partially enlarged view showing a portion A in FIG.

 FIG. 7 is a partially enlarged view showing a portion A in FIG.

 FIG. 8 is a partially enlarged view showing a portion B in FIG.

 FIG. 9 is a partially enlarged view showing a portion A in FIG.

 FIG. 10 is a sectional view taken along the line ZZ in FIG.

 FIG. 11 is a partially enlarged view showing a portion B in FIG.

 FIG. 12 is an overall configuration diagram showing a conventional plastic oil converting apparatus.

 FIG. 13 is a partially enlarged view showing a gasifier of a conventional plastic oiler. FIG. 14 is a longitudinal sectional view showing another embodiment of the gasification furnace of the present invention. FIG. 15 is a sectional view taken along line AA in FIG.

 FIG. 16 is a graph showing the relationship between the temperature and the pressure in the gasification furnace shown in FIG.

 FIG. 17 is an overall configuration diagram showing one embodiment of the plastic oil converting apparatus according to the present invention.

FIG. 18 is a sectional view taken along line AA in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings.

 FIG. 1 is a longitudinal sectional view showing an embodiment of a novel gasification furnace 19 constituting a part of the waste plastic oil converting apparatus of the present invention, and FIG. 2 is a sectional view taken along line X--X in FIG. .

 As shown in the figure, the gasifier 19 has a kiln-shaped furnace body 20 provided with a waste plastic inlet H, an opening / closing mechanism 21 for opening and closing the inlet H, and heating this from the outside. And a heating means 22 integrally provided, and these are covered with a heat insulating casing 23.

 The furnace body 20 is entirely made of a metal having excellent heat resistance, corrosion resistance and heat conductivity, for example, Hastelloy® stainless steel or superalloy. Is heated and melted by the heating means 22 to be thermally decomposed, and the pyrolyzed gas is sequentially supplied from the gas outlet 20a to the above-described oiling section side.

 The opening / closing mechanism 21 presses the plate-shaped shirt 24 opening and closing the waste plastic inlet H and the shutter 24 against a sealing surface S formed on the periphery of the inlet H. It consists of fixing means 25.

As shown in FIGS. 3 and 4, this chassis has a heat-resistant rectangular shape similar to the rectangular opening H, and at least sufficiently larger than the opening area of the opening H. The wheels 26, 26, 26, 26 (or one or two) are provided in pairs on each side (four in total). By traveling along a pair of rails 27, 27 extending to the upper side, it moves horizontally with respect to the inlet H. Further, brackets 28, 28 extending in a direction perpendicular to the moving direction are provided on both sides of the end of the shirt 24, and are provided with a pair of hydraulic cylinders 29, 29 from a pair of hydraulic cylinders 29, 29. The sliding means allows the shirt 24 to slide horizontally to open and close the inlet H. That is, one end of each of the hydraulic cylinders 29, 29 is connected to the brackets 28, 28 of the chassis 24, and the other end of the hydraulic cylinders 29, 29 is a bracket 30, on the side of the input location 23a. The bracket is fixed to 30 and hydraulic brackets start from these brackets 30 and 30. By simultaneously expanding and contracting the cylinders 29 and 29, the opening and closing of the shirt 24 is controlled as shown in FIG.

 As shown in FIGS. 1 and 2, the fixing means 25 includes a pair of front and rear hydraulic cylinders 31, 31, 31, 31, which are vertically supported and erected on the upper side of the loading location 23 a. 1 and U-shaped holding claws 32, 32, 32, 32 provided at the respective corners of the shirt Yuichi 24, and when the shirt Yuichi 24 is closed, these holding claws are formed. 32, 32, 32, 32 and the cylinder rods 33, 33, 33, 33 of the respective hydraulic cylinders 31, 31, 31, 31 are engaged with each other, and their holding claws 32, 32, 32, 32 are engaged. Is pressed against the sealing surface of the inlet H by the piston rods 33, 33, 33, 33, thereby fixing the shirt 24 and sealing the inlet H.

 That is, as shown in FIGS. 5 to 8, each of the cylinder rods 33, 33, 33 is provided with a disc-shaped flange portion 34, and after the pressing claw 32 is fitted into the biston rod 33. The cylinder rod 33 is extended, and the collar 34 forcibly pushes down the presser claw 32, so that the shirt 24 is strongly adhered to the seal surface S of the inlet H at each corner of the four-point power station. ing. After the inlet H is sealed by the shirt 24 as described above, when it is slid, it can be easily released simply by pulling the cylinder rod 33 upward.

Also, when the shutter 24 is forcibly pushed down to the slot H in this manner, if the rails 27, 27 supporting the shirt 24 are fixed, the upper and lower portions of the shutter 24 will be fixed. The movement is regulated via the wheels 26, 26, 26, 26. Therefore, in the present invention, as shown in FIG. 1 and FIG. 3 and the like, the rails 27, 27 are divided into two in the longitudinal direction, and the divided rails 27a, 27a on the input port H side are shown in FIG. The split rails 27a, 27a are moved up and down together with the shirt Y24 as shown in FIG. The structure is such that it does not regulate the movement of people. As shown in FIG. 5, the ends of the split rails 27a, 27a are connected by an H-shaped connecting beam 36, and another flange 37 is connected to the cylinder rod 33. By connecting the connecting beam 36 to the flange 37, the split rails 27a and 27a are simultaneously moved up and down as the cylinder rod 33 moves up and down. May be.

 As shown in FIG. 11, a purge gas header 38 is provided at the periphery of the charging port H of the furnace body 20 so as to extend along the entire circumference thereof. By spraying a purge gas supplied from a waste tank, etc. through the slit 39 opened at the upper part of the seal surface of the inlet H, even if a part or waste of waste plastic adheres and accumulates on the seal surface H, This can be forcibly removed by the pressure of the purge gas. The slit 39 is provided with a guide piece 40 through which a purge gas flows in the direction of the seal surface H. The guide piece 40 is formed in a flexible plate-like shape, and a When opening and closing the 24, it easily deforms and does not interfere with the shirt.

 On the other hand, as shown in FIG. 1, FIG. 2 and FIG. 10, the bottom of the furnace main body 20 has an uneven (wave) shape in which a plurality of gutter-like members 2 O b, 20 b. At the end of each of the gutter-shaped members 2 O b, 2 O b, etc., and also has a gutter-shaped discharge passage 20 c for merging therewith. It is about 1 Z 27 増 大 times larger than the area of the flat plate.

 Further, in each of these gutter-shaped members 20b, 20b... And the discharge path 20c, screw conveyors 41, 41 extending in the longitudinal direction thereof are rotatably arranged coaxially. Insoluble matter accumulated in the furnace bottom, for example, solid matter such as earth and sand, metal, glass, etc., or sludge is forcibly removed from the furnace bottom wall. From 20 b... Through a discharge path 20 c, the gas is discharged to the outside from a discharge hole 42 formed in the casing 23. The exhaust hole 42 is provided with an on-off valve (not shown), which is closed during normal operation so that the melt or pyrolysis gas in the furnace body 20 does not leak out from the exhaust hole 42. It goes without saying that this is the case.

The screw conveyors 41, 41 provided in each of the gutter-shaped members 2Ob, 20b ... are arranged such that when the end of the rotating shaft extends through the casing 23 to the outside. At both ends, pulleys 4 3, 4 3… are provided at the ends thereof, and each pulley 4 3, 4 3… is connected to a collecting motor 4 4 fixed outside the casing. The screw conveyors 4 1, 4 1,... Are simultaneously and rotationally driven in the same direction by being bridged and connected to each other by a belt 45.

 The screw conveyor 41 provided on the discharge path 20c also has a rotating shaft end extending through the casing 23 to the outside, and a pulley 46 provided at the end thereof. The screw conveyor 41 'is rotated by connecting the unloading motor 47 fixed outside the casing to the unloading motor 47 by means of a belt 48.

 Further, as shown in Fig. 11, strip-shaped reinforcing plates 49, 49 ... extending in the longitudinal direction are provided between the gutter members 20b, 2Ob ... respectively. In addition, a metal thermometer 50 is embedded in the reinforcing plate 49, and the strength of the bottom of the furnace body 20 is secured by the reinforcing plates 49, 49. Thus, the furnace bottom temperature can be detected at any time. The measurement report of the metal thermometer 50 is inputted to a control unit for controlling the output of the gas burner described later at any time.

 On the other hand, as shown in FIGS. 1 and 2, a heating means 22 for heating the furnace body 20 is provided in a combustion chamber 51 located below the furnace body 20 and in the combustion chamber 51. The gas burner 52 is formed by a gas burner 52 and a jacket 53 that covers the periphery of the furnace body 20 with a certain gap. The body 20 is heated from the bottom thereof, and the combustion exhaust gas is guided to the jacket 53 communicating with the combustion chamber 51, and the exhaust gas is discharged to the outside from the exhaust gas outlet 54 at the top of the jacket 53, thereby surrounding the side surface. Thus, the structure is such that the furnace body 20 is heated.

Further, according to the present invention, a partition plate 55 for spirally partitioning the inside of the jacket 53 is provided in the jacket 53, and the high-temperature combustion exhaust gas flowing into the jacket 53 side is directly discharged to the exhaust gas outlet 5. Instead of flowing through the furnace 4, the combustion exhaust gas is spirally flown around the furnace body 20 by the partition plate 5 5, so that the high-temperature combustion exhaust gas and the furnace body 20 are in contact with each other for as long as possible. In FIGS. 1 and 2, reference numerals 56 and 57 denote manholes and lids for opening and closing the combustion chamber, 58 and 58 support legs for supporting the decomposition furnace, and 59 a furnace body. A hopper is provided for facilitating the introduction of waste plastic into 20. A viewing window 60 is provided for checking the inside of the combustion chamber 51.

 In the gasification furnace 19 of the present invention having such a structure, first, the shutter 24 for closing the inlet H of the furnace body 20 is operated by the hydraulic cylinder 31 and the presser claw 32. As a result, it is strongly pressed against the sealing surface S of the inlet H and is closed in a state where it comes into close contact with it. Since a gap is formed on the surface S, it is possible to reliably prevent the inconvenience caused when the harmful thermal decomposition gas leaks and the surrounding environment is deteriorated.

 In addition, a purge gas header 38 is provided at the periphery of the inlet H, and when closing the shirt 24, high-pressure purge gas is blown from the purge gas header 38 onto the sealing surface S to put waste plastic. Even if a part of the waste plastic or dust adheres to the seal surface S at the time, etc., this will be surely removed, so that it is possible to reliably avoid the generation of the gap on the seal surface S due to the adhesion of the dust and the like. it can.

 In addition, the furnace bottom of the furnace body 20 is formed by arranging a plurality of gutter-like members 2 Ob in an uneven (corrugated) shape to increase the surface area thereof, thereby allowing contact between the hot combustion gas immediately after generation and the furnace bottom. Since the area is increased, the heating rate of the furnace body 20 is improved, and efficient melting-pyrolysis can be achieved. Further, by providing the gutter-shaped member 20b and the like with the screw conveyor 41, solid matter or sludge deposited on or attached to the furnace bottom is forcibly brought into contact with the furnace bottom wall and easily removed. This eliminates the need for cumbersome manual removal work as in the past, and at the same time allows the furnace body 20 to be removed in a high-temperature state, thus shortening the furnace downtime and increasing Operational efficiency can be maintained.

In addition, a metal thermometer 50 for measuring the temperature of the furnace bottom is provided at the furnace bottom, so that the temperature of the entire furnace body 20 can be accurately measured together with the conventional thermometer in the furnace. Can be measured. For example, if the difference between the temperature of the furnace bottom measured by the metal thermometer 50 and the temperature inside the furnace body 20 by the furnace thermometer is small, it is determined that gasification is in progress and the operation is continued and the temperature difference When exceeds a certain value, it can be determined that gasification has ended.

 In the initial operation method of the waste plastic cracking furnace of the present invention, water is added at the same time as or before and after the introduction of waste plastic, as in the case of the above-mentioned conventional one. ), The contact area between the input waste plastic and the furnace bottom (furnace wall) is reduced, and heat transfer (melting) may not be performed well in the initial stage. Therefore, for example, if a small amount of high-boiling oil obtained from reclaimed oil or the like is further added together with this water, the high-boiling oil evaporates following the evaporation of water, resulting in waste plastic and heat transfer surfaces (furnace walls). Even when the contact area is small, heat is transferred well, and efficient heating and melting can be achieved.

 Next, Fig. 14 shows a new gasification furnace for gasifying so-called infectious waste plastic, which is likely to have infectious pathogens, such as syringes, among the waste plastics mentioned above. 60 is a longitudinal sectional view showing one embodiment, and FIG. 15 is a sectional view taken along line AA in FIG.

 As shown in the figure, the gasification furnace 60 is a vertical cylindrical furnace body 61 that pyrolyzes infectious waste plastic to generate a pyrolysis gas, and the furnace body 61 is heated from below. It mainly comprises heating means 62 and stirring means 63 for stirring the inside of the furnace body 61.

First, the furnace body 61 is entirely made of a metal having excellent heat resistance, corrosion resistance and heat conductivity, for example, Hastelloy® stainless steel or superalloy. It is a pressure vessel with hemispherical end plates 65, 66 above and below 4 respectively. The upper end plate 65 has an input port 67 for inputting the waste, and the input port 67 can be opened and closed by a flanged opening / closing lid 68. . Further, a water supply pipe 69 for supplying water for initial melting is connected to the input port 67, and the water supply pipe 69 can be opened and closed by an electromagnetic valve V. Further, a gas outlet 70 is formed above the body portion 64, and the pyrolysis gas generated in the furnace main body 61 flows to the above-described oil treatment tank 2 side. Further, an automatic opening / closing valve 71 is provided at the gas outlet 70, and the gas outlet 70 is automatically opened / closed under certain conditions as described later.

 Further, an insoluble matter discharge port 72 is provided on the bottom end plate 66 side of the furnace body 61, so that insoluble matter such as earth and sand, metal pieces, etc. accumulated at the bottom of the furnace body 61 can be appropriately taken out. It is like that.

 Next, the heating means 62 includes a combustion chamber 73 located at the bottom of the furnace main body 61, and a jacket 74 covering the periphery of the furnace main body 61 from the combustion chamber 73. 7 Heating equipment provided in 3 75, for example, a furnace that directly heats the furnace body 61 from the bottom with a gas burner, oil burner, electric heater or the like, and a device that uses fossil fuel such as a gas burner, oil burner, etc. When the high-temperature combustion gas generated in the combustion chamber 73 when used as the heating equipment 75 flows from the jacket 74 to the exhaust gas outlet 76 side, the furnace body 61 can be heated evenly from the surrounding area. It has become.

 On the other hand, a stirrer 63 provided in the furnace body 61 is mounted on a drive shaft 77 located at the axial center of the furnace body 61, and mounted on the top to rotate the drive shaft 77. Drive shaft 78 and a plurality of stirring blades 79, 79, 79, 79 extending radially from the lower end of the drive shaft 77, and are introduced into the furnace body 61. By heating the infectious waste plastic evenly while stirring it, it melts efficiently. As shown in FIG. 2, the stirring blades 79, 79, 79, 79 are formed so that the tips thereof are curved downstream in the rotational direction, and the bottoms of the stirring blades 7 The bottom of the furnace is in constant contact with the bottom of the furnace, and when it rotates, it slides on the bottom of the furnace such as a scraper to prevent the adhesion and accumulation of sticky and insoluble materials on the bottom of the furnace. ing.

Next, an example of an operation method of the gasification furnace 60 of the present invention having such a structure will be described. First, as shown in Fig. 14, the inlet port 67 at the top of the furnace body 61 is opened, and infectious waste plastic to be treated and a small amount of water are charged into the furnace body 61, and the gas outlet 70 The furnace body 61 is heated by the heating means 62 while the stirrer 63 is driven with the automatic opening / closing valve 71 and the valve V of the water supply pipe 69 closed, that is, with the furnace body 61 sealed.

 Then, due to this heating, the water with the lower boiling point starts to evaporate in the furnace body 61 first, and the pressure and temperature in the furnace body 61 gradually increase as shown in Fig. 16 with this evaporation. By appropriately adjusting the heating means 62, the inside of the furnace body 61 is adjusted to a pressure and a temperature at which infectious pathogens die, for example, a saturated pressure at 121 ° C of water as shown in the figure, and this state is maintained for a certain period of time. For example, hold for about 20 minutes. As a result, infectious pathogens adhering to the waste plastic will be completely sterilized by high-pressure steam sterilization in the furnace body 61, and will flow out to the liquefaction tank 2 together with the pyrolysis gas alive. There is nothing like that.

 Next, when the condition for infectious pathogens to be completely killed is reached in this way, the automatic opening / closing valve 71 of the gas outlet 70 is gradually opened and the inside of the furnace body 61 is opened as shown in FIG. At the same time, the output of the heating means 62 is raised to raise the furnace temperature. Then, in the furnace body 61, the waste plastic is melted following the evaporation of the initially charged water, and the temperature rises further and reaches the gasification temperature, for example, about 380 ° C. Is thermally decomposed and gasified, and the pyrolyzed gas is sent from the gas outlet 70 to the sequential oil treatment tank 2 side, where it is separated into oil and water by the same treatment as before, and is effectively used as regenerated oil etc. Become.

 As described above, in the gasification furnace 60 according to the present invention, the inside of the furnace body 61 can be kept in a high-temperature, high-pressure sealed state for a certain period of time. Even in the case of so-called infectious waste plastics such as catheters and catheters, the infectious disease-causing bacteria can be pyrolyzed safely and reliably without leaking to the outside while alive.

If all of the waste plastics in the gasification furnace 60 were pyrolyzed in this manner, the same processing would be repeated in a batch manner. If insoluble matter (solid matter) such as metal pieces such as injection needles or earth and sand gradually accumulates in the furnace body 6 1, open the insoluble matter discharge port 7 2 at the bottom of the furnace body 6 1 By rotating the stirring blade 79 of the step 3, the insoluble matter can be easily taken out. This makes it possible to easily eliminate the inconvenience caused by the insoluble matter adhering and accumulating on the bottom of the furnace main body 61 to deteriorate the heat transfer efficiency or to reduce the furnace volume.

 Next, FIGS. 17 and 18 show another embodiment of the waste plastic oil converting apparatus according to the present invention.

 As shown in the figure, this waste plastic oiling device is composed of a gasification furnace 80 that heats and melts waste plastic to generate a pyrolysis gas, as in the conventional device, and a pyrolysis gas generated in the gasification furnace 80. It is mainly composed of an oil treatment tank 81 for condensing and separating gas.

 First, as shown in FIGS. 1 and 2, the gasification furnace 80 is provided with a heating means 83 for heating the furnace body 82 from the outside in a furnace body 82 having an inlet H at the top. That is, various mixed waste plastics (limited to thermoplastics) introduced from the inlet H are heated and melted by the heating means 83, gasified, and the pyrolysis gas is discharged from the gas outlet 84. The oil is sent to the oil treatment tank 81 via the gas line G1. A sealing lid 85 is hingedly connected to the end of the charging port H of the furnace body 82, and a switching mechanism such as a motor cylinder provided between the bottom side thereof and the inner wall of the furnace body 8 is provided. 6 can be freely opened and closed.

The bottom of the furnace body 82 is formed in a valley shape toward the center thereof, and a screw conveyor 87 extending horizontally is provided at the bottom of the valley. As shown in FIG. 2, the screw conveyor 87 integrally includes a helical screw 89 around a rotating shaft 88 extending along the longitudinal direction of the valley bottom. One end of 88 is connected to a drive motor 90 provided outside through the furnace main body 82, and the drive motor 90 rotates the drive motor 90 in any direction. Further, a discharge hole 91 is formed at the other end of the rotating shaft 88, and the discharge hole 91 is openably and closably closed by a discharge cover 92. O

 The heating means 83 for heating the furnace body 82 is made up of three planar sheets 93, 94, 95 as shown in FIG. 1, and is located at the bottom of the furnace body 22. The flat heat sinks 94, and the flat heat sinks 93, 95 provided on both slopes sandwiching the bottom are operated independently.

 —The liquefaction treatment tank 81 is designed to liquefy and temporarily store the pyrolysis gas introduced from the gas line G1, and to introduce it into the horizontally long water tank 96 from the gas line G1. The jet scrubber 97 has a structure that includes a jet scrubber 97 that blows cooling water onto the pyrolyzed gas that has been condensed and a cleaning tower 98 that cleans and exhausts unliquefied gas that has not been liquefied by the jet scrubber 97. ing.

 Further, the bottom of this water tank 96 is narrowed in a funnel shape, a drain line L1 is connected to the bottom at the bottom through a valve V1, and a valve V The oil recovery line L 2 is connected via 2.

 This drain line L1 is provided with a strainer 199 and a circulation pump 100, which drains water from the water tank 96 and circulates it to the above-mentioned ditto scrubber 197 and washing tower 98 side. At the same time, a part thereof is returned from the return line L3 to the gasification furnace 80 side. The return line L3 and its branch are provided with electromagnetic valves V3, V4, V5, V6 for opening and closing the lines L1, L3, the scrubber line L4, and the washing tower line L5. Is provided.

 The drain line L1 is provided with a neutralizing agent tank 101 via a branch line L6 and a valve V7. The neutralizing agent is injected into the water extracted from the water tank 96. To neutralize this. The scrubber line L4 is provided with a cooling water line L9 and a valve V9, which are branched from the cooling water line L9 to supply cooling water (tap water) to the jet scrubber 97. ing. Further, a reclaimed oil tank 102 is provided in the oil recovery line L2, and the regenerated oil separated in the water tank 96 is drawn out from the oil recovery line L2 and stored.

The washing tower 98 is provided with an upper spray nozzle 104, Demisu Yu 105, a lower spray nozzle 106, and a baffle plate 107 in the vertically elongated tower body 103 in order from the top. Clean the pyrolysis gas that has not been completely liquefied by the washing water (water, etc.) flowing from the washing tower line L5 and washing water line L10 before sending it to the exhaust line L7. I'm sorry. The exhaust line L7 is provided with a preheater 108 and a catalytic deodorizer 109. The gas after cleaning is heated by the preheater 108 before the catalytic deodorizer 108. At 9 it is deodorized and released into the atmosphere.

 In the figure, 110 is a level meter for measuring the liquid level in the water tank 96, and 111 is a permeation type liquid level meter for visually observing the separation state of oil and water. Reference numeral 112 denotes a heat insulating material, which prevents the gas line G1 between the gasifier 80 and the oil treatment tank 81 from cooling.

 Next, the operation of the thus configured plastic oil liquefaction apparatus of the present invention, that is, a method of treating waste plastic will be described.

 First, when processing waste plastic, instead of immediately putting waste plastic into the gasifier 80, put a small amount of water into the furnace body 82 of the gasifier 80 before that. The furnace body 82 is heated with the opening / closing lid 85 closed and the inside of the furnace body 82 sealed. In this initial stage, it is not necessary to operate all the planar heaters 93, 94, 95 of the heating means 83, and only one of them, for example, the heater 94 at the bottom, is activated.

 Then, the water charged into the furnace main body 82 evaporates as steam by the heating, flows from the gas outlet 84 through the gas line G1 into the liquefaction treatment tank 81, and further the oil All of the air in the system will be expelled by flowing from the chemical treatment tank 81 to the drain line L1, oil recovery line L2, exhaust line L7, and so on.

 Next, if the inside of the apparatus is replaced with steam in this way, the valve V1 of the drain line L1 on the side of the oil treatment tank 81 and the valve V2 of the oil recovery line L2 are closed. Open the opening / closing lid 85 of the gasification furnace 80 again, put the waste plastic to be treated into the furnace body 82 from the inlet H, and close the opening / closing lid 85 again to clean the inside of the furnace body 82. After sealing, the furnace body 8-2 is heated by the heating means 83.

This heating melts and liquefies the waste plastic charged into the furnace body 82, and then sequentially pyrolyzes it into pyrolysis gas, and then from the gas outlet 84 to the gas line G 1 And reaches the jet scrubber 97 in the oil treatment tank 81. At this time, as shown in Fig. 18, the inside of the furnace can be completely sealed by fastening the open / close lid 85 to the furnace body 82 with bolts B etc., so that the leakage of pyrolysis gas is completely prevented. In addition, it is possible to safely treat even infectious waste plastic such as a syringe as described above.

 After that, the pyrolysis gas that reaches the jet scrubber 97 is quenched and liquefied by contacting the cooling water supplied from the drain line L 1 and the branch line L 4 with gas and liquid, and becomes regenerated oil. The water is sequentially stored in the water tank 96 together with the cooling water. In addition, when heating and melting the waste plastic in the gasification furnace 80, if the screw conveyor 97 is rotated, the inside thereof is agitated, and good heating and melting is achieved. In addition, since the pyrolysis gas is cooled by the ditto scrubber 97, even if the substance solidifies from a direct gas such as terephthalic acid, it is not clogged, and a good gas flow is secured. It becomes possible. That is, if a fin tube type heat exchanger or the like is used instead of the jet scrubber 97, for example, a substance that directly solidifies, such as terephthalic acid, is generated in the tube, and this is formed in the tube. Although there is a risk of accumulation and blockage, the use of the jet scrubber 97 does not cause inconveniences such as blockage due to the blow-off of the jet water even if it solidifies near the outlet. It is.

 On the other hand, unliquefied gas (pyrolysis gas) that could not be liquefied by the jet scrubber 97 passes through the upper space of the water tank 96 as it is, is washed by the washing tower 98, and then is discharged into the exhaust gas line. Deodorized in L7, purified and released to the atmosphere.

Then, when all of the waste plastic put into the gasification furnace 80 becomes pyrolysis gas and flows out to the oil treatment tank 81, the heating of the furnace body 82 is stopped. However, at this time, if insoluble matter (solid matter) such as earth and sand, metal, wood chips, etc. is included together with the waste plastic that has been put in, this remains at the bottom of the furnace and reduces the furnace volume, For example, heat transfer from the heating means 83 may be deteriorated. Therefore, if such insolubles have accumulated to some extent, the lid 92 of the discharge hole 91 at the bottom of the furnace is opened as shown in Fig. 18 and the screw conveyor 87 is driven. If this is done, the insoluble matter collected at the bottom is conveyed to the discharge hole 91 side and can be easily discharged from the discharge hole 91 as it is, eliminating the need for operators to clean the inside of the furnace as in the past. Become.

 On the other hand, the mixture of the cooling water and the regenerated oil accumulated in the water tank 96 of the oil treatment tank 81 is then separated for specific gravity in the water tank 96 by leaving it for a while, that is, the specific gravity of the liquid surface side First, open the valve V 2 of the regenerated oil line L 2 and flow the regenerated oil from the upper layer to the regenerated oil tank 102 in order to separate the phases so that small regenerated oil collects and water with a high specific gravity collects at the bottom. Thus, only the regenerated oil can be effectively separated and recovered. After that, if a certain amount of regenerated oil is removed, the water in the lower layer will be extracted from the drain line L1 as cooling water for the next process and reused, but at this time, terephthalic acid solids etc. As shown in the figure, if substances or oils with a higher specific gravity than water are contained, they are collected in a layer at the bottom of the water layer.When water in the water layer is reused, components having a higher specific gravity must be drained beforehand. By extracting the waste oil from the waste oil line L8 branched from the upstream side of L1, only the substance having a specific gravity can be recovered. At the same time, the water in the water layer can be reused as the water for initial charging in the gasifier 80 and the cooling water for the jet scrubber 97, as described above, making it possible to use resources effectively. . In addition, if chlorine or the like is contained in the extracted water, oxidative corrosion of the piping system constituting each line may be caused, so caustic soda must be removed from the neutralizer tank 101 in advance. Can be reused after neutralizing by adding an appropriate amount of a neutralizing agent.

 When the recovery of the reclaimed oil is completed in this way, new waste plastic is put into the gasification furnace 80, and the heating and gasification treatment as described above is performed in a batch manner to achieve the type. Regardless, most waste plastics can be treated and used effectively.

 In this embodiment, electric planar heaters 93, 94, 95 are used as the heating means 83 of the gasification furnace 80, but a gas burner or the like may be used instead. good.

Claims

The scope of the claims

1. A plasticizer that has a gasifier that heats and melts waste plastic to generate a pyrolysis gas, and an oilification tank that liquefies and separates the pyrolysis gas generated by the gasifier. In the apparatus, the gasification furnace is provided with a heating means for heating the inside of the furnace main body at the bottom of a kiln-shaped furnace main body having a waste plastic inlet at an upper part, and an opening / closing mechanism for opening and closing the furnace at the inlet. The opening / closing mechanism includes a plate-shaped shutter that is at least larger than the opening area of the inlet, and fixing means that presses and fixes the shutter against a sealing surface of the inlet peripheral edge. A plastic oil liquefaction unit characterized by the following:

 2. The plastic oiling device according to claim 1, further comprising a sliding means for sliding the shirt horizontally in the evening to open and close the inlet.

 3. The plastic oil according to claim 1, wherein the slide means is a hydraulic cylinder having one end connected to the shutter side and the other end swingably connected to the furnace body side. Device.

 4. The plastic oil according to claim 1, wherein the fixing means is a hydraulic cylinder that presses and fixes the shutter against the seal surface from above.

5. The plastic oil converting apparatus according to claim 1, wherein a purge gas header that blows a purge gas to a sealing surface is provided on a peripheral portion of the charging port.

 6. The plasticizer according to claim 1, wherein the bottom of the furnace body is formed in an uneven shape in which a plurality of gutter-like members are arranged in parallel.

 7. The gutter-shaped member has a gutter-shaped discharge passage at an end thereof and a screw conveyer in each of the gutter-shaped member and the discharge passage. A plastic oil converting device according to item 1.

8. The heating means comprises a gas burner, and a jacket for flowing combustion exhaust gas from the gas burner is provided around the furnace body, and the jacket is screwed to the jacket. The plastic oiling device according to claim 1, further comprising a spiral partition plate.

9. Plasticized oil with a gasifier that heats and fuses waste plastic to generate pyrolysis gas, and an oil treatment tank that liquefies and separates the pyrolysis gas generated in this gasifier In the apparatus, the gasification furnace is a vertical cylindrical furnace body into which infectious waste plastic is charged, and the furnace body is heated from the periphery thereof to thermally decompose infectious waste plastic to generate a pyrolysis gas. A heating means, and a stirrer for stirring the inside of the furnace main body, and at the top of the furnace main body, an inlet for charging the infectious waste plastic, an opening / closing lid for opening and closing the same, and discharging the pyrolysis gas. A plastic oiling device comprising a gas outlet and an automatic on-off valve at the gas outlet.

 10. The furnace main body was a pressure vessel having a vertical cylindrical metal body and upper and lower hemispherical metal end plates, and provided with the open / close lid and gas outlet at the top. 10. The plastic oil converting apparatus according to claim 9, wherein:

 The stirrer comprises: a drive shaft positioned at the axis of the furnace body; a drive motor for rotating the drive shaft; and a plurality of stirring blades extending radially from the drive shaft. 10. The apparatus according to claim 9, wherein the rotating blades rotate while contacting the bottom surface of the furnace body.

 12. The plastic oil liquefaction apparatus according to claim 9, wherein a discharge port for discharging insoluble matter is provided at a bottom portion of the furnace main body. .

 1 3. A gasification furnace that generates pyrolysis gas by simultaneously heating and melting many types of waste plastics, and an oilification tank that condenses and separates the pyrolysis gas generated by this gasification furnace In the plastic oil converting apparatus, the gasification furnace is characterized in that a bottom surface thereof is narrowed in a valley shape and a screw conveyor and a hole for discharging solids are provided at the bottom.

14. The oil treatment tank is equipped with a horizontally long water tank, a jet scrubber that blows cooling water onto the introduced pyrolysis gas and condenses it, and a washing tower that cleans exhaust gas. Has a funnel shape and a drain line is connected to the bottom 14. The plastic oil liquefaction apparatus according to claim 13, wherein an oil recovery line is connected to a middle part of the water tank.

 15. The plasticizer according to claim 14, further comprising a neutralizer tank for injecting a neutralizer into the drain line.